Thermal Spray Coatings for Electromagnetic Wave Absorption and Interference Shielding: A Review and Future Challenges

This review aims to consolidate scattered literature on thermally sprayed coatings with nonionizing electromagnetic (EM) wave absorption and shielding over specific wavelengths potentially useful in diverse applications (e.g., microwave millimeter wave, solar selective, photocatalytic, interference shielding, thermal barrier-heat/emissivity). Materials EM properties such as electric permittivity, magnetic permeability, electrical conductivity, dielectric loss are critical due which a material can respond absorbed, reflected, transmitted, or may excite surface waves at frequencies typical of radiations. Thermal spraying is standard industrial practice used for depositing where the layer formed by successive impact fully partially molten droplets/particles exposed high moderate temperatures velocities. However, an emerging novel application existing spray techniques, some special considerations warranted targeted development involving relevant characterization. Key potential research areas relating selection coating fabrication strategies their practices field identified. The study shows gap feedstock materials design doping, complex covered that be advancing exploiting properties.